Clutch mechanism



Oct. 29, 1935. R. M. COOPER AL CLUTCH MECHANISM Filed Dec. 30, 1931 INVENTORaT Patented 0.1. 29, 1935 UNITED STATES PATENT OFFICE:

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0 pally, Cleveland, Ohio, a corporation 01 301110 Application December3., 1931; Serial No. 583,894 2 Claims. (Cl- 193-53) This inventionrelates to clutch m for use in change speed mechanisms.

It is an object of this invention to provide a simple and efllcientclutch mechanism for use in a change speednmechanism of a pre-selectivetype.

It is a further object of this invention to provide a clutch mechanismfor a change speed mechanism which can be actuated with facility toeffect a change in speed in the mechanism driven by the change speedmechanism without disconnecting the change speed mechanism from themechanism driven thereby or from the mechanism which drives it.

It is a further object of this invention to provide a clutch mechanismfor a change speed mechanism which embodies means for preventing theestablishment of a driving connection effecting a speed change untilafter the parts to be connected have been brought into substantialsynchronism.

Other objects and attendant advantages will appear in the followingdescription, when read in connection with. the accompanying drawing. in

which:

Figure 1 is a top plan view of a gear box for an automobile constructedwith a clutch mechanism embodying the present invention, the upper partof the casing of the gear box being removed so as to show the internalmechanism.

Figure 2 is a longitudinal sectional view of a sleeve first illustratedin Figure 1, the section being taken through theaxis of the sleeve at anangle to show the parts of the sleeve hidden in Figure 1.

Figure 3 is a composite view consisting of a vertical sectionof the gearbox taken on a line corresponding with line 3-3 of Figure 1, and avertical section of a forwardly disposed shifting mechanism takenthrough the central axis of such mechanism.

Figure 4 is a vertical section taken on line 4-4 of Figure 1, certainparts falling within the section but not shown in Figure 1 beingshown indot and dash lines, and

Figure '5 is a diagrammatic view showing the shape and relation of theteeth formed on three associated parts of the change speed mechanism,the parts being illustrated in the same relation as in Figure 3. V

The gear box illustrated in the drawing comprises a casing consisting ofan upper section 11 I and a lower section l8. Mounted in aperturescomposed of semi-circular recesses formed in the end walls of thesections 11 and 18, there are two sets of axially aligned anti-frictionbearings, a

left hand set as viewed from the forward end of r the gearbox'consisting of a forward hearing I! and a rearward bearing 20, and aright hand set as viewed from the same position consisting of a forwardbearing 2| and a rearward bearing 22. a Journalled in the bearing I!there is a drivenshaft 23 formed at its rear end with a gear wheel 24.Mounted within the bearing 24, there is a shaft 25 the forward end ofwhich is supported inan anti-friction bearing 28 mounted in a re- 10'cess formed in the rear end of the shaft 23; and mountedupon the shaft25 for relative rotation with respect thereto, there is a gear wheel 21of a smaller pitch diameter than the gear wheel 1 24. Journalled withinthe bearings 2| and 22, 15 there is a eountershaft 28 formed with gearwheels 28 and 30 which mesh respectively with gear wheels 24 and 21.

The gears 24 and 21 are formed. with opposed sets of rectangular shapedclutch teeth 3| and 32 20 respectively; and splined upon the shaft 25between the gears 24 and 21 there is a sleeve 33 formed at its oppositeends with rectangular shaped teeth 34 and 35 designed to meshrespectively with the teeth 3| and 32 of the gears 25 24 and 21, thesleeve being of such length that when it occupies a position midwaybetween the gears 24 and 21 the teeth at its opposite ends are 1 and anintermediate pair of diametrically spaced,

longitudinally extending, S-shaped members 38 formed on their oppositesides with longitudinally spaced shoulders 39. The cylindrical portions31 40 are formed at their outer end with slots 40 which act duringshifting of the sleeve 33, as hereinafter described, to facilitate theremoval of lubricant from between the beveled end surfaces of theportions 31 and the corresponding surfaces of the ears 24 and 21.

Secured to the sleeve 33 by means of screws 4|, and located between theS-shaped portions 38 of the sleeve 36, there is a pair of arcuatemembers 42 disposed in circular alignment and formed with alignedgrooves 43, the ends of such members being spaced apart a slightlygreater distance than that required to permit the broad sections of theS-shaped portions 38 to slide therebetween. These arcuate members aredesigned to engage u with the shoulders 33, as hereinafter described, toforce the sleeve 35 into frictional engagement with the gears 24 and 21,and are so constructed and arranged that, when they are moved intoengagement with the shoulders 35, the sleeve 33 is moved to a positionmidway between the gears 24 and 21 with its teeth out of engagement withthe teeth of both such gears.

Successful operation of the speed change mechanism is dependent upon'thecondition that a greater amount of friction be set up between the sleeve36 and the gears 24 and 21 than is set up between the members 42 and theshoulder 33, when the former parts are forced into engagement byengagement of the latter part as above described; and it is to this end,that the sleeve 36 and the gears 24 and 21 are formed with beveledsurfaces to increase the friction between such parts, and the sleeve 36formed with slots 40 to facilitate the removal of lubricant from betweenthe beveled surfaces of such parts.

Slidably mounted in bearings 44 and 45 in the upper section l1 of thetransmission casing, there is a rod 46; and supported upon this rodthere'is a shifter fork 41, the lower forked end of which straddles theshaft 25 and extends into the grooves 43 in the members 42. The shifterfork 41 is slidably mounted upon the rod 48 between two springs 48 and43 of equal strength, placed under compression, and held againstlongitudinal movement with respect to the rod 45 by collars 58 securedin position by pins 5|.

The rod 46 extends through the forward end of the upper section ll ofthe transmission casing, and is connected with a forwardly extending rod52 which extends into the casing 53 of an auxiliary shifting unit. Therod 52 is slidably supported in bearings 54 mounted in the side walls ofthe casing, and is formed within the casing with'shoulders 55 and 55designed for engagement with the side walls of the casing to limitbackward and forward movement thereof.

Pivotally mounted in the upper end of the casing l3 by means of a balland socket construction, there is a manually operated lever 51 forshifting the rods 52 and 46. This lever extends through a. slot formedin the rod 52 between the shoulders 55 and 56, and is formed within theslot with a circular enlargement 58 which engages the end walls of theslot to form a pivotal connection of the sliding type.

Pivotally connected to the bottom of the casing 53, and to the lower endof the lever 51 below the rod 52, there is a spring operated mechanismconsisting of a telescopic two-part casing 59 and an internally mountedspring 60 of relatively great strength placed under compression inassembly. This spring operated mechanism is so coordinated with thelever 51 as to urge further inclination of the lever when inclined froma vertical position, and is so designed as to render it substantiallyimpossible for the lever to occupy an intermediate position between theposition shown and an alternate position with the shoulder 55 of the rod52 engaging the side wall of the casing 53, unless the lever is held insuch a position.

The. shifting mechanism just described in the preceding three paragraphsis so coordinated with the sleeves 33 and 36, and the sleeves 33 and 36so constructed, that whenever the parts occupy a position as illustratedin Figure 3, or an alternate position with the lever 51 in a forwardposition and the sleeve 33 in engagement with the gear 21, the sleeve 33is held in position by a differenceinthepresmresofthespringsuandfl withthe ends of its teeth engaging the surfaces between the teeth of the,respective geara.

Ininstallingthegearboximtdescribedwithin an automobile, the shaft 23 isconnected with 5 mechanism forming a driving connection between it andthe engine of the automobile, and

the shaft 25 with mechanism for transmitting motion to the tractionwheels of the automobile. In operation, the engine of the automobiledrives 10 the shaft 23 which is caused to rotate in the directionindicated by arrows in the drawing for forward motion of the vehicle,andin the reverse direction for rearward motion of the vehicle. With thesleeve 33 occupying the position shown 15 in the drawing, the drive fromthe engine is transmitted directly from the shaft 23 to the shaft 25with no change in speed, the mechanism being in what is commonly knownas direct drive. With the sleeve 33 occupying a position with its teeth20 35 in mesh with the teeth 32 of the gear 21, the drive is transmittedthrough the gears 24 and 23 to the countershaft 23 and from thecountershaft through the gears 35 and 21 in the shaft 25 with the resultthat the shaft 25 is driven at 25 a higher rate of speed than thedriving shaft 23. The mechanism is then in what is known as overspeeddrive.

Assuming that the automobile is in forward motion and that the sleeve 33and the lever 51 30 occupy the positions shown in Figure 3, the sleevemay be shifted to a position with its teeth 35 in mesh with the teeth 32of the gear 21 by moving the lever 51 to a forward position in which theshoulder 55 on the rod 52 engages the side 35 wall of the casing 53, andthen decelerating the engine. As the lever 51 is moved forward the rods52 and 46 are moved rearward reducing the pressure of the rearwardlydisposed spring 43 on the fork 41, and increasing the pressure of the 40forwardly disposed spring 46 on such member, until at the end of themovement of the lever 51 the difference in pressure of the springs 43upon the fork is such as to tend to move the fork and the sleeve 33rearwardly. Rearward movement 45 of the sleeve 33 and the fork 41 isprevented by the friction set up between teeth 3| of the sleeve 33 andthe teeth 34 of the gear 24 in transmitting the drive, and as a resultfurther movement of the parts of the shifting mechanism is delayed 50pending deceleration of the engine.

Upon deceleration of the engine, the pressure on the teeth 3| of thesleeve 33 and the-teeth 34 of the gear 24 is removed, and the sleeve 33is moved rearwardly by the great rp 'essure of the for- 55 wardlydisposed spring 48 to a position where the ends of the members 42 engagethe rear shoulders 33 of-the S-shaped portion 38 of the sleeve 36, andthe beveled end surface of the sleeve 36 has been forced into frictionalengagement with w the beveled surface of the gear 21.

Since the shaft 25 will be rotating at a slower speed than the gear 21at the time the sleeve 33 is forced into frictional engagement with thegear 21, the sleeve 33 will tend to be rotated 65 through its frictionalengagement with the gear 21 at a more rapid rate than the shaft 25. As aresult, the rear shoulders 39 of the S-shaped portions 38 of the sleeve36 will be momentarily maintained in engagement with the ends of themem- 7o bers 42 holding the sleeve 33 against further rearward movement.As the engine continues to decelerate, the relative speeds of the shaft25 and the gear 21 will be reversed, and the sleeve 36 will then beturned through its frictional en- 15 gagement with the gear 21 to movethe rear shoulder 39 of the S-shaped portions 33 out of engagement withthe ends of the members 42. As soon as the members 42 have'been movedout of engagement with the shoulders" of the S-shaped portion 33, thesleeve 33 will be moved rearward by the action of the forwardly disposedspring 49 bringing its teeth 35 into engagement with the teeth-'32 ofthe Bear 21.

Due to the fact that the members 42 are released from the rear shoulders39 of the S-shaped portions 33 closely following the time at which thespeed of the sleeve 33 is exactly the same as that of the gear 21, l.e., closely following the reversal of the relative speed of the shaft 25and and then accelerated. The forward movement of the rod 49 produced bythe rearward movement of the lever 51 decreases the pressure of theforwardly disposed spring 43 on the fork, and increases the pressure ofthe rearwardly disposed spring 49 on such member, until at the end ofthe movement the difference in pressures of the springs 49 and 43 uponthe fork is such as to tend to produce forward movement of the fork andthe sleeve 33. Forward movement of the sleeve 33 and the fork 41 isprevented, in an analogous manner to the corresponding movement in thepreviously described operation, by the friction set up between the teeth35 of the sleeve 33 and the teeth 32 of the gear 21 in transmitting thedrive.

Upon deceleration of the engine, the pressure on the teeth 35 of thesleeve 33 and the teeth 32 of the gear 21 is removed, and the sleeve 33is moved forwardly by the greater pressure of the rearwardly disposedspring 49 to a position where the ends of the members 42 engage theforwardly disposed shoulders 39 of the S-shaped portions of the sleeve36, and the beveled end surface of t the sleeve 36 has been forced intofrictional engagement with the corresponding surface of the gear 24.

Due to the fact that the shaft 25 will be rotating at a higher rate ofspeed than the gear 24 at the time the sleeve 36 is forced intofrictional engagement with the gear 24, the friction set up between thegear 24 and the sleeve 36 will tend to retard the speed of rotation ofthe latter part, and in consequence thereof, the shoulders 39 of theS-shaped portions 38 of the sleeve 36 will be held in engagement withthe ends of the membars 42 preventing further forward movement of thesleeve 33. Following acceleration of the engine, the relative speeds ofrotation of the gear 24 and the shaft 25 will be reversed, and thesleeve 36 will then be turned through its frictional engagement with thegear 24 to move the forward shoulders 39 of the S-shaped portions 39 outof engagement with the ends of the members 42; following which, thesleeve 33 will be moved forward by the action of the rearwardly disposedspring 49 bringing its teeth 3| into engagement with the teeth 34 of thegear 24.

Owing to the fact that the members 42 are released from the shoulders 39of the s-shaped portions 33 closely following reversal of speeds of theshaft 25 and the gear 24, the sleeve 33 will be turning at but aslightly slower rate of speed than the gear 24 at brought intoengagement with the teeth 34 of such gear. As a result, the teeth 3| ofthe sleeve 33 will go quietly into mesh withthe teeth 34 of the gear 24in an analogous manner to the manner in which the teeth 35 of the sleeve33 enter into engagement with the teeth 32 of the gear 21 in shifting tooverspeed drive.

Except during shifting which should be quickly performed withouthesitation, the operating lever 51 should either occupy the positionshown or the alternate position for overspeed drive. In case the lever51 is retained in an intermediate position, it may happen that theconditions, at the time'the lever is moved to one or the other of theabove positions, will besuch that the sleeve 33 is not retained in anintermediate position pend-' ing a reversal of its speed and the speedof the gear toward which it is urged, and that at the time the sleeve 33is brought into engagement with the gear the difference in relativespeeds will be such as to produce serious damage.

Should the lever 51 be shifted from one-position to another while theautomobile is standing still, and a drive established between the engineand the shaft 23 with the'engine-in operation, it will either result inthe-sleeve 33 being retained in a disconnected position between thegears 24 and 21 through engagement of the members 42 with the shoulders39, or in the sleeve being moved into a position with its teeth inengagement with the teeth of the gear toward which it is urged beforethe shaft 23 has reached a speed of rotation capable of producing damagethe result being dependent upon the direction in which the shaft 23 isdriven. I 4

Although the foregoing description is necessarily of a detailedcharacter, in order that the invention may be completely set forth, itis to be understood that the specific terminology is not intended to berestrictive or confining, and that 45 various rearrangements of partsand structural details may be resorted to without departing from thespirit and scope of the invention.

We claim as our invention:

1. In a change speed device having a shaft, a large gear and a smallgear mounted in co-axial relation with said shaft, 'and meansoperatively connecting said gears for simultaneous rotation' atdifferent speeds, a clutch mechanism comprising a sleeve slidablymounted upon said shaft between said gears and aflixed upon said shaftfor simultaneous rotation therewith, a set of teeth formed on one end ofsaid sleeve designed for engagement with teeth on said large gear and aset of teeth formed on the other end of said 60 sleeve designed forengagement with teeth on said small gear, said sleeve being so designedthat when it occupies a position midway between said gears the teeth atits opposite ends are out of engagement with the teeth of both of saidgears, 05 a pair of spaced lugs on said sleeve, a member slidably androtatably mounted on said sleeve, said member having a length greaterthan said sleeve and less than the distance between said gears,and'being constructed with end portions designed for frictionalengagement with said gears and with an intermediate portion whichextends between said lugs,-a laterally extending abutment formed on oneside of the intermediate portion of said member which when said sleeveis 7 the time its teeth 3| are 5.

moved by continuously acting force from van interlocked position withsaid large gear toward an interlocked position with said small gear isengaged by one of the lugs on said sleeve movina said member intofrictional engagement with said small gear and which acting throughengagement with the aforesaid lug stops and retains said sleeve in aposition midway between said gears until after there has been a reversalof speeds of said shaft and said small gear acting through thefrictional engagement set up between said member and said small gear tomove the aforesaid lug out of engagement with said abutment, and alaterally extending abutment formed on the other side of theintermediate portion of said member designed to co-act with the other ofsaid lugs in an analogous manner to that set up when said sleeve ismoved by a continuously acting force from an interlocked position withsaid small gear toward an interlocked position with said large gear.

2. In a change speed device having a shaft, a large gear. and a smallgear mounted in co-axial relation with said shaft, and means operativelyconnecting said gears for simultaneous rotation at different speeds, aclutch mechanism comprising a sleeve slidably mounted upon said shaftbetween said gears and ailixed upon said shaft for simultaneous rotationtherewith, a set of teeth formed on one end of said sleeve designed forengagement with teeth on said large gear and a set of teeth formed onthe other end of said sleeve designed for engagement with teeth on saidsmall gear, said sleeve being so designed that when it occupies aposition midway between 2;O19,073 said gears the teeth at its oppositeends are out of engagement with the teeth of both of said gears, amember slidably and rotatably mounted on said sleeve, said member havinga length greater than said sleeveand less than the distance between saidgears, and being constructed with end portions designed for frictionalengagement with said gears, and means for guiding relative movement ofsaid member and said sleeve whereby said member inmoving between thelimits of its longitudinal movement with respect to said sleeve isconstrained at the ends of such movement to direct longitudinal movementand at an intermediate point to rotative movement in one direction, saidmeans comprising mechanism carried by said sleeve which when said sleeveis moved by a continuously acting force from an interlocked positionwith one of said gears towards an interlocked position with the other ofsaid gears is brought into engagement with abutting means on said memberforcing said member into frictional engagement with the gear towardswhich said sleeve is moved, and which through being brought intoengagement with said abutting means acts to stop and retain said sleevein a position midway between said gears until after there has beena,reversal of the speeds of said shaft and the gear towardswhich saidsleeve is moved acting through the frictional engagement set up betweensaid member and said last named gear to produce relative rotationalmovement of said sleeve and said member.

ROLLAND M. COOPER. WILLIAM a. serum

